As the variety of available computing devices increases, and as the size of many of these devices decreases, there comes a need to adapt the ways in which users interact with these computing devices. People increasingly utilize portable devices such as cellular phones, personal digital assistants (PDAs) and other electronic devices, which present different challenges than conventional stationary devices such as desktop computers. For example, portable devices typically are powered by a battery that has a limited operational time. For devices with large display elements or processor-intensive functionality, for example, usage can drain the batteries relatively quickly. Even for devices that can be plugged into a wall socket or powered using other conventional mechanisms, however, it still can be desirable to reduce the power consumption of these devices.
Certain conventional devices utilize various inactivity-based approaches, such as turning off a display of a cellular phone if a user does not interact with an input element such as a keypad, touch-sensitive display or roller ball for a determined period of time. Such an approach is not optimal, as the user can become frustrated if the display shuts off too quickly or while the user is viewing content on the device.
Further, users of devices such as smart devices and cellular phones often trigger undesired actions by inadvertently causing specific keys or other input mechanisms to be activated when placing the devices into a pocket, purse, backpack, etc. Any particular movement can cause an action to occur, such as a phone to dial an emergency number or a smart device to continually illuminate the display element. Thus, in addition to reducing power consumption, it can be desirable to limit the functionality of various devices in certain situations.